A fast-moving fire damaged one of Philadelphia’s best-known cheesesteak shops early Friday, but authorities say no injuries were reported.

Dozens of firefighters and other emergency responders went to Jim’s Steaks on South Street when the fire was reported around 9:30 a.m. Smoke could be seen pouring from the building, but officials said all the employees were able to safely evacuate the structure.

It wasn’t immediately known how many people were in the building when the fire broke out.

The cause of the fire remains under investigation.

Jim’s Steaks opened its original location in Philadelphia in 1939. The South Street location opened in 1976.